Zinc gluconate in the treatment of dysgeusia--a randomized clinical trial

In the treatment of dysgeusia, the use of zinc has been frequently tried, with equivocal results. The aim of the present randomized clinical trial, which involved a sufficiently large sample, was therefore to determine the efficacy of zinc treatment. Fifty patients with idiopathic dysgeusia were carefully selected. Zinc gluconate (140 mg/day; n=26) or placebo (lactose; n=24) was randomly assigned to the patients. The patients on zinc improved in terms of gustatory function (p <0.001) and rated the dysgeusia as being less severe (p <0.05). Similarly, signs of depression in the zinc group were less severe (Beck Depression Inventory, p <0.05; mood scale, p <0.05). With the exception of the salivary calcium level, which was higher in the zinc patients (p <0.05), no other significant group differences were found. In conclusion, zinc appears to improve general gustatory function and, consequently, general mood scores in dysgeusia patients.     

Validation of a Chinese version of the dental anxiety inventory

OBJECTIVES: To translate the English version of Dental Anxiety Inventory (DAxI) and its short-form (SDAxI) and to validate their use in Hong Kong Chinese. METHODS: The DAxI and SDAxI were translated into Chinese. A total of 500 adults (18-64 years) were interviewed, the Chinese DAxI, Symptom Checklist 90 (SCL-90), Depression Anxiety Stress Scales (DASS) and State-Trait Anxiety Inventory (STAI) were completed. Based on their initial DAxI scores, 135 interviewees were invited to attend a dental examination 1 month later. Then, the subjects completed the DAxI again, together with Beck Anxiety Inventory (BAI) which measured the state anxiety level of the participants. Two months after the initial interview, all 500 subjects were asked to complete the DAxI again. Another 300 adults were recruited and interviewed for the SDAxI validation. RESULTS: Cronbach's alpha of the Chinese DAxI and SDAxI were 0.77 and 0.80 and the test-retest correlation coefficients were 0.90 and 0.84, respectively. High correlation between BAI and DAxI scores and its stability over time supported construct validity of the Chinese DAxI. Small positive correlations between the DAxI and other subscales of the SCL-90, DASS and STAI supported discriminant validity of the instrument. The SDAxI demonstrated comparable validity and reliability with DAxI. CONCLUSION: The translated Chinese DAxI demonstrated good validity and reliability. It is available for use in dental anxiety research in adult Chinese. In situations where a short-form is desirable, the Chinese SDAxI is a simple, valid, reliable and interpretable scale for measuring dental anxiety in both research and dental practice.     

Initial subgingival colonization of 'pristine' pockets

The treatment of periodontitis/peri-implantitis involves the reduction/eradication of periopathogens. After therapy, beneficial and pathogenic species recolonize the subgingival area. The dynamics of recolonization and especially the role of the supragingival environment in this process are still not well-understood. This prospective, split-mouth study followed the early colonization of 'pristine' pockets created during implant surgery (16 partially edentulous patients), to record the time needed before a complex subgingival flora could be established with the supragingival area as the single source. Four subgingival plaque samples were taken from shallow and medium pockets around implants (test), and neighboring teeth (undisturbed microbiota as reference) 1, 2, and 4 wks after abutment connection. Checkerboard DNA-DNA hybridization and culture data revealed a complex microbiota (including several pathogenic species) in the pristine pockets within a wk, with a minimal increase in counts up to 4 wks. Analysis of these data demonstrated that, even with the supragingival environment as the single source for colonizing bacteria, a complex subgingival microbiota can develop within 1 wk.     

Science and technology in Turner's Georgian dentist's rooms

Turner's painting of a dental surgeon's rooms, discussed in the first of these two papers,(1) is a very satisfying work of art, successful in its relaying of a domestic drama, and also fulfilling Payne Knight's commission to produce a work to equal that of the older masters. It cannot, though, be relied upon to show us what a late Georgian dentist's rooms actually looked like. For this we are very fortunate to have Turner's sketchbook, with its preparatory drawings for the painting.     

Multi-unit fixed partial denture for a bilateral cleft palate patient: a clinical report

Patients with cleft palates eventually require definitive fixed or removable dental prostheses after the maintenance of arch alignment and occlusal relationship during adolescence. This case report presents application of a resin composite veneered fixed partial denture utilized as a definitive prosthesis for a bilateral cleft palate patient after stable occlusion had been established orthodontically. The composite veneered long span fixed partial denture provides adequate aesthetics and function.     

Resonance frequency analysis of one-stage dental implant stability during the osseointegration period

BACKGROUND: Currently, there is no available clinical tool to evaluate the amount of osseointegration and stability around dental implants. It has been recently suggested that changes in the stiffness of an implant in bone during healing may be monitored by using resonance frequency analysis (RFA). The aim of this study was to determine whether RFA can be integrated into the routine clinical evaluation of initial healing of dental implants. METHODS: Thirty-one patients (18 female and 13 male; mean age of 51.7 years) were included into this study. A total of 122 implants and three different, but comparable, implant designs were evaluated by using RFA. The specific transducer for each implant system was used. ISQ (implant stability quotient) readings were obtained for each implant at the time of surgery, 3 and 6 weeks postoperatively, and at the time of loading (3 or 6 months following surgery). Data were analyzed for different healing times, various anatomical locations, implant length, and type. Average time in function was 12 months. RESULTS: Two implants failed during healing. Implant stability was higher on the mandible compared to the maxilla for each implant system studied (Mann-Whitney test, P <0.01). ISQ readings decreased significantly at 3 and 6 weeks post-surgery compared to readings obtained at surgery (Wilcoxon matched pairs sign-rank tests, P <0.01). A recovery to the initial ISQ levels was noted at the time of implant loading. The possible effects of different types and lengths of implants to ISQ readings were examined. CONCLUSIONS: Results of this study support the need for a clinical tool to evaluate dental implant stability prior to loading, especially for implants placed in the maxilla. It appears that implant stability is weakest at 3 to 6 weeks in one-stage non-loaded dental implants. ISQ readings can be used to determine different healing phases and the stability of dental implants. However, it is difficult to define a general standardized range of ISQ readings for successful implant integration for various implant systems. Thus, RFA values/ISQ levels should be calibrated for each implant system separately. Further studies are needed to compare the early changes seen in immediately loaded dental implants and to determine whether there is any time in which the total recovery in ISQ levels may occur.     

Behavioral strategies in pediatric dental treatment. A necessity?

The American Academy of Pediatric DEntistry is regularly publishing updates of protocols and guidelines. The article Dutch summary of and comment on a special issue of the journal Pediatric Dentistry with evaluated protocols and articles on guidelines for dentists. The protocols have been adapted to modern insights, but not very practical described. To use these protocols and guideliness in Dutch pediatric dentistry, it is advocated to take into consideration the individual child's age and behaviour and to base one's strategies on data of randomized clinical trials.     

Insoluble zinc, cupric and tin pyrophosphates inhibit the formation of volatile sulphur compounds

Oral malodour is mainly a result of the production of volatile sulphur compounds (VSC). The present study was concerned with investigating the anti-VSC effect of insoluble pyrophosphates (PP) of zinc, copper(II) and tin(II). The hypothesis to be tested was that the sulphide anions produced when VSC are solubilized in water have a higher affinity for the respective metal ions than the PP anion. The anti-VSC effects of insoluble PP were compared with the corresponding soluble metal salts using three in vitro methods: saliva putrefaction; dialysis of a suspension of PP and saliva against water; and analysis of water containing hydrogen sulphide and methyl mercaptan gases, and gases in the headspace. The levels of VSC were analysed by gas chromatography in the first and third methods, and released metal ions were analysed by atomic absorption spectroscopy in the second. The results showed that: the insoluble metal PP inhibited VSC formation in saliva by 99-100%; under dialysis, only minute amounts of metal ions are released from the combination of PP and saliva; and the PP lost their metal cations in water containing dissolved gases and inhibited VSC formation. Hence, the results support the experimental hypothesis. Sulphide ions are obviously very strong ligands for these metal ions.     

Cadherin-related neuronal receptors in incisor development

Cadherins are cell adhesion molecules that are critical for tissue development. In this report, we identified members of the cadherin family cadherin-related neuronal receptors (CNRs) 1 and 5 expressed in rat incisors by the differential display method. Quantitative RT-PCR revealed that CNR1 mRNA is expressed in the secretory stage but reduced in the early-maturation stage, while CNR5 mRNA is expressed in both these stages. In situ hybridization showed that strong expression of CNR1 is strong in the secretory stage, but reduced in the early phase and diminished in the late phase of the early-maturation stage. CNR5 mRNA is expressed almost at the same levels in the secretory and in the early phase of the early-maturation stages but is absent in the late phase of the early-maturation stage. Both CNR1 and 5 mRNA are continuously expressed in odontoblasts. Immunohistology showed that CNR proteins are expressed in the secretory and early-maturation stages of ameloblasts, but no protein expression at the late-maturation stage was observed. CNR proteins were continuously expressed in odontoblasts. We found that recombinant CNR1 binds dental epithelial and mesenchymal cells through N-terminal domain EC1 in vitro. These results suggest that CNR1 and CNR5 may play an important role in enamel and dentin formation, probably through cell-cell and/or cell-matrix interactions.     

Static and cyclic loading of fiber-reinforced dental resin.

OBJECTIVE: The aim of this study was to evaluate the flexure strength of unidirectional fiber-reinforced resins under static and cyclic loading with and without thermal cycling. METHODS: The fiber-reinforced resin materials chosen for this project were commercially available endodontic posts and commercially procured bar samples. For all materials, controls for flexure strength were tested in air and in water using three-point loading. Specimens were thermal cycled between 7 and 63 degrees C for 6000 cycles. A staircase approach was used to determine the flexure fatigue limit and scanning microscopy was used to examine the microstructure. RESULTS: The carbon/graphite fiber-reinforced resin posts and the glass FiberKor posts were significantly stronger than the ceramic (zirconia) and the other glass-reinforced resin materials. Thermal cycling caused a significant lowering (11-24%) of the flexure strength for each resin based post system. The ceramic post system decreased only by 2%. Further, for standard size glass fiber-reinforced resin bars, no significant differences between testing in air and water was observed, but a significant difference between static and cyclic loading was noted. SIGNIFICANCE: The decreases in the strength property due to thermal cycling and the cyclic loading of these materials indicates that their utilization in the oral environment enhances their degradation, and potentially shortens their clinical life.